Gas and material studies
Contacts: B. Mandelli, G. Morello, F. Renga, S. Roth,D, Piccolo, A. Pastore, B. A. Gonzalez
WG3 Indico category: https://indico.cern.ch/category/16509/
Contact email: DRD1-WG3-convenors@cern.ch
The DRD1 Working Group 3 (WG3) aims to address key issues related to gas and material studies that are common to all the existing gaseous detector tech- nologies in the development of future gaseous detectors. As a matter of fact, gas mixtures and materials are fundamental components to obtain high-performance gaseous detectors. This working group offers the potential to establish common goals, collaborations and facilities for the different gaseous detector technologies to achieve better performance and to foresee possible limitations, which may pre- vent their use in future experiments. The essential topics, common research interests and strategic infrastructures needed to advance the knowledge in this field are briefly described in the following.
TOPICS COVERED BY THE WG3
According to an open consultation of the worldwide Physics scientific community involved in the development and use of gaseous detectors, four major research categories have been identified as research areas of interest for the DRD1 WG3:
a) Gas: Accurate measurements of specific gas properties are at the base of R&D on gaseous detectors. Among others, studies related to photon emis- sion by gases, gas molecules and mixtures eco-compatibility and their chem- ical characterization are a strong need for the community. Improvements or new results on key parameters such as scattering cross sections, transport co- efficients both at atmospheric or high pressures or scintillation mechanisms are fundamental for designing and simulating future gaseous detectors. Due to concerns about the environment as well as fluorinated gases (F-gases) availability and costs, the search and characterization of new environmentally- friendly gas components will be an essential ingredient. The studies of gases with high scintillation light yield will also be important for future detector development. The main topics identified in this research area are gas prop- erties, eco-gas studies and light emission in gas.
b) Systems for gaseous detectors: For the operation of gaseous detectors, it is fundamental to have reliable gas systems for small to big experiments. In view of future applications and experiments, the use of gas recirculation and recuperation system will play a key role to reduce consumption when expensive or greenhouse gases have to be used. Furthermore, the gas quality will be fundamental for detector performance and long-term operation. The investigation in the use of sealed detectors or small recirculation systems DRAFT could also be considered a good solution for small experiments, low-rate ap- plications and laboratories, where in the future it could be difficult to use expensive or greenhouse gases. The main topics identified in this research area are gas systems, gas recirculation and recuperation systems, sealed de- tectors and systems.
c) Materials: Studies on materials are fundamental for improved performance and long-term operation of the detectors. The use of resistive material has played a crucial role in the last years for a stable detector operation and rate capability, and it will be essential also for future applications where the use of novel material could lead to several improvements. In this context the studies on solid converters and photocathodes need to be addressed for the improvement of spatial and time resolution but also for radiation hardness. In view of the construction of future systems, one should neither neglect stud- ies on material properties for both detectors and infrastructures nor engineer- ing studies, as for example precision mechanics and the use of low-budget 36 material. The main topics identified in this research area are resistive elec- trodes, solid converters, photocathodes, novel materials, material properties for detectors and infrastructures, light (low-budget) materials and precision mechanics.
d) Long-term operation: Guarantying gaseous detector stable operation and optimal performance over decades is fundamental for future accelerators and it requires extensive studies on detector long-term operation in an environ- ment that could accelerate the conditions foreseen in future experiments, es- pecially in term of radiation. This can be achieved with dedicated studies on current and gas-induced ageing effects as well as on the radiation hardness of the components in use together with the evaluation of possible contributions from material outgassing. This research area will focus on all these aspects relevant to all gaseous detector technologies. The main topics identified in this research area are detector ageing, radiation hardness and outgassing.
Among the aforementioned research topics, some of them appear to spark interest in the large majority of the gaseous detector scientific community. In particular, the following topics have been identified as being of major interest for most of the gaseous detector communities, where synergies can also be found:
• Gas properties: huge cross-technology interest, focussing on different as- pects related to the gas used, for example, studies on cross-section, transport parameters, chemical characterization, discharges and operation at differ- ent pressures. A strong interest has also been expressed in simulation (see WG4)
• Eco-gases: widespread interest in the study of new environmentally-friendly gas mixtures, their chemical characterization and contribution to the detector ageing.
• Ageing and outgassing: huge cross-technology interest, in view of next long-term experiments, even in combination with high-rate environments.
• Gas systems: widespread interest for all technologies. Gas systems are seen as fundamental infrastructure for big detector systems or when using expen- sive or greenhouse gases. In this context, research interest is moving towards recirculation and recuperation gas systems for all technologies as well as im- proving gas purity.
• Novel materials: widespread interest for all technologies to search for ma- terial to improve detector performance. The common interest in resistive materials for MPGD and RPC, devoted in particular to very high-rate appli- cations, as well as for low material budget in TPCs and Wire chambers.
• Precision mechanics: of wide interest especially in view of new experi- ments where new detector systems will be built. It ranges from mechanics for E and B field alignments to the construction of large detector volumes and systems.
It is worth noting that the common interests in the topics are in full agreement with the ECFA Detector R&D Themes [1] as it will be described in the next Section.