Speaker
Description
The Multi Wire Proportional Chambers (MWPC) have found wide application due to their ability to instrument large areas, with a rate capability of up to a few hundred kHz/cm^2. While MWPCs remain a robust solution today, their scalability is limited by the time-consuming wire-stringing process and the decreasing availability of expertise. This significantly increases production cost for large systems, such as muon detectors at future $\textrm{e}^{+}\textrm{e}^{⁻}$ colliders. MicroStrip Gas Chambers (MSGCs) introduced photolithographic techniques for detector construction, paving the way for Micro-Pattern Gaseous Detectors (MPGDs) and enabling the transition from manual assembly to industrial fabrication.
The MultiStrip Proportional Chamber (MSPC) is a novel detector concept that combines the MWPC principle of operation with MSGC-inspired photolithographic fabrication. It is designed to simplify construction and enable industrial-scale production while maintaining MWPC-like performance.
The MSPC active volume is defined between a cathode PCB and a flat electrode hosting the amplification stage. The latter consists of metallic strips photolithographically patterned on a resistive substrate (glass or Diamond-Like Carbon (DLC)), replacing the wire structure of MWPCs. Two configurations have been implemented: anodic (sense) strips ($\sim30\ \mu m$), or alternating anodic (sense) and cathodic (field) strips ($\sim100\ \mu m$), both with $2\ mm$ pitch. The sense electrode width provides stable proportional amplification and the sense-field distance suppresses streamer formation. The resistive substrate enables charge evacuation during avalanches and reduces charging-up effects. A backplane electrode on the opposite side of the substrate shapes the electric field and improves charge collection.
The use of DLC as a resistive substrate represents a key advancement with respect to traditional MSGCs based on resistive glass ($10^9-10^{11}\ \Omega\cdot cm$). The lower DLC resistivity ($10^6-10^{9}\ \Omega/\Box$) can be tuned to optimize charge evacuation, mitigating further charging-up effects while preserving stable operation and improving the rate capability.
In 2026, a first batch of $5\times6\ cm^2$ prototypes was produced and tested, operating with Ar:CO$_2$ gas mixtures (90:10 and 70:30). Results for both configurations will be presented in terms of detection efficiency and stability over time. These results indicate that the MSPC offers a scalable, wire-free alternative to MWPCs for mid-rate applications, reducing assembly complexity while maintaining comparable performance. This approach is well suited for large-area detector systems, where production cost and manpower are critical constraints.
| Name of the speaker | Matteo Giovannetti |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | yes |