G. Hamar

Cosmic Muon Detection for Geophysical Applications

A portable cosmic muon detector has been developed for environmental, geophysical, or industrial applications. The device is a tracking detector based on the Close Cathode Chamber, an MWPC-like technology, allowing operation in natural underground caves or artificial tunnels, far from laboratory conditions. The compact, low power consumption system with sensitive surface of 0.1 m2 measures the angular distribution of cosmic muons with a resolution of 10 mrad, allowing for a detailed mapping of the rock thickness above the muon detector. Demonstration of applicability of the muon telescope (REGARD Muontomograph) for civil engineering and measurements in artificial underground tunnels or caverns are presented.

Close Cathode Chamber technology for cosmic particle tracking

The Close Cathode Chamber (CCC) technology has been developed and found useful in a portable tracking system under harsh and varying environmental conditions due to their mechanical and operational stability. The muon flux have been measured on ground and at shallow depths underground (< 70 m.r.e.) which provides a good reference for other experiments. The multiple scattering in rock and the soft contamination of the track sample have been investigated experimentally and by GEANT4. The applicability of the sensor to detect underground rock density inhomogeneities has been demonstrated via reconstruction of an underground tunnel system. A modified muon tomograph has been built with sensitive area of 0.25 m2 and angular resolution of 15 mrad which is useful for material discrimination via the measurement of multiple scattering and absorption of muons. The reliable tracking performance, low power consumption and fair angular resolution make the CCC technology useful also in large area tracking detectors.

Cosmic muon detector using proportional chambers

A set of classical multi-wire proportional chambers were designed and constructed with the main purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and at the same time are low cost, making them ideal for educational purposes. The detector layers have efficiencies above 99% for minimum ionizing cosmic muons, and their position resolution is about 1 cm, that is, particle trajectories are clearly observable. Visualization of straight tracks is possible using an LED array, with the discriminated and latched signal driving the display. Due to the exceptional operating stability of the chambers, the design can also be used for cosmic muon telescopes.

Status of COMPASS RICH-1 Upgrade with MPGD-based Photon Detectors

A Set of new MPGD-based Photon Detectors is being built for the upgrade of COMPASS RICH-1. The detectors cover a total active area of 1.4 m 2 and are based on a hybrid architecture consisting of two THGEM layers and a Micromegas. A CsI film on one THGEM acts as a reflective photocathode. The characteristics of the detector, the production of the components and their validation tests are described in detail.

High Efficiency Gaseous Tracking Detector for Cosmic Muon Radiography

A tracking detector system has been constructed with an innovative approach to the classical multi-wire proportional chamber concept, using contemporary technologies. The detectors, covering an area of 0.58 square meters each, are optimized for the application of muon radiography. The main features are high (>99.5%) and uniform detection efficiency, 9 mm FWHM position resolution, filling gas consumption below 2 liters per hour for the non toxic, non flammable argon and carbon dioxide mixture. These parameters, along with the simplicity of the construction and the tolerance for mechanical effects, make the detectors to be a viable option for a large area muography observation system.