Speaker
Description
The SONGS (SOlar Neutron Gaseous Spectrometer) project aims to develop an innovative fast neutron spectrometer based on proton tracking within a Micro-Pattern Gaseous Detector (MPGD), with potential application as a solar physics probe in Low Earth Orbit.
Solar fast neutrons, produced by interactions between solar energetic particles and the solar atmosphere, provide a direct probe of particle acceleration mechanisms during impulsive events such as solar flares and coronal mass ejections, with important implications for space weather. Existing space-based detectors, typically based on scintillator arrays or fiber trackers, are mainly limited to neutron flux measurements and lack accurate spectroscopic and directional capabilities, while also featuring relatively small effective areas.
To overcome these limitations, we propose a detector that exploits the technique of double elastic neutron–proton scattering in hydrogen-rich materials, enabling the reconstruction of both the energy and direction of the incident neutrons. The concept combines a large-volume (2-3 dm3) MICROMEGAS (MM) detector with high-granularity readout and an array of thin plastic scintillator tiles, readout by silicon photomultipliers, inserted into the gas cell as active targets to induce neutron scattering. Recoil protons escaping from the scintillator travel through the gas between the tiles, producing ionization tracks extending over several centimeters, which are reconstructed in three dimensions via time and position measurements on the MM anode plane.
A preliminary simulation of the SONGS prototype was developed using GEANT4 interfaced with Garfield++ to optimize the detector design and identify the configuration that maximizes energy and angular resolution as well as the effective area. The results of simulations indicate that this approach can outperform existing neutron fiber trackers systems.
This contribution presents the detector concept, detailed simulation studies, and the first experimental validation from beam tests performed at the CERN SPS. The measurements were carried out using a MICROMEGAS prototype with a 10 cm-thick drift region and a field cage integrated along the lateral side of the active volume to ensure stable and uniform electric field conditions. The readout system is based on SRS/VMM3a electronics. Preliminary results focus on tracking performance, including spatial resolution and initial assessment of angular reconstruction capabilities.
Future work will focus on integrating plastic scintillator tiles within the MICROMEGAS drift volume, optimizing their geometry and compatibility with the electric field configuration. An overview of these ongoing and future developments will be presented.
| Name of the speaker | Paolo Maestro |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | no |