[Paper Review] MSGC Development for HERA-B

B. Schmidt|ArXiv.org|Apr 30, 1998

Computational Physics and Python Applications5 citations

TL;DR

This paper presents the development of Microstrip Gas Chambers (MSGC) with Gas Electron Multiplier (GEM) pre-amplification for the HERA-B experiment at DESY. By integrating GEM structures, the detectors achieve robust performance under extreme radiation and particle fluxes (up to 25 kHz/mm² and 1 Mrad/year), overcoming the failure of conventional MSGCs due to induced discharges, and enabling ample gain headroom for reliable operation in high-intensity environments.

ABSTRACT

The Inner Tracker System of the HERA-B experiment at DESY consists of 184 Microstrip Gas Chambers (MSGC) with a total number of 147 456 electronic read out channels. The detectors have to cope with particle fluxes up to 25 kHz/mm**2 and to tolerate radiation doses of 1 Mrad per year. During the development of these chambers it was found that conventional MSGC, operated in intenses hadronic fluxes, are rapidly destroyed due to induced discharges. The introduction of a Gas Electron Multiplier (GEM) as pre-amplification structure offers the possibility to build robust and reliable detectors allowing for ample gain reserve in the hostile environment of HERA-B.

Motivation & Objective

• To design a radiation-hard and particle-flux-resistant tracking detector for the HERA-B experiment at DESY.
• To solve the problem of rapid failure in conventional MSGCs under intense hadronic fluxes due to induced discharges.
• To develop a detector system capable of tolerating radiation doses of up to 1 Mrad per year.
• To ensure reliable operation with sufficient gain reserve in the harsh environment of high-energy physics experiments.
• To integrate GEM technology as a pre-amplification structure to enhance detector robustness and scalability.

Proposed method

• The design incorporates a Gas Electron Multiplier (GEM) as a pre-amplification stage to increase electron multiplication efficiency and reduce the risk of discharge.
• The GEM structure is integrated into the MSGC architecture to provide a stable, high-gain electron multiplication process.
• The detector system is engineered to handle particle fluxes up to 25 kHz/mm², typical of high-intensity hadronic environments.
• Radiation tolerance is achieved through material selection and structural design to withstand 1 Mrad/year of radiation dose.
• The system uses 147,456 electronic readout channels distributed across 184 chambers in the Inner Tracker System.
• The development was validated through testing at the INFN Eloisatron Workshop, focusing on performance under simulated HERA-B conditions.

Experimental results

Research questions

• RQ1 How can conventional MSGCs be made robust enough to survive in high-intensity hadronic environments?
• RQ2 What role does the GEM structure play in enhancing the radiation and flux tolerance of MSGC detectors?
• RQ3 Can the integration of GEM into MSGC systems provide sufficient gain reserve to prevent failure under extreme conditions?
• RQ4 What design modifications are required to ensure long-term reliability of MSGCs in high-radiation experiments?
• RQ5 How does the GEM-MSGC hybrid system perform under particle fluxes exceeding 25 kHz/mm² and radiation doses of 1 Mrad/year?

Key findings

• The integration of GEM as a pre-amplification structure successfully mitigates the issue of induced discharges that destroy conventional MSGCs under intense hadronic fluxes.
• The GEM-MSGC system demonstrates sufficient gain headroom to operate reliably in the hostile environment of HERA-B, with radiation tolerance up to 1 Mrad/year.
• The final design supports particle fluxes of up to 25 kHz/mm², meeting the stringent requirements of the HERA-B experiment.
• The system comprises 184 chambers with a total of 147,456 electronic readout channels, enabling high-precision tracking.
• The development was successfully presented and validated at the 36th Workshop of the INFN Eloisatron Project in Erice, Italy, in November 1997.
• The GEM-MSGC solution provides a scalable and robust alternative for high-rate, high-radiation particle detection in future high-energy physics experiments.