Speaker
Description
In the context of the ESA/M-MATISSE mission, the French Institute for Research in Astrophysics and Planetology (IRAP) has initiated the development of SPAM, a particle detector instrument to be deployed on two Mars-orbiting spacecraft. Designed to characterize both electrons and ions in the Martian environment, SPAM targets an energy range of 30 keV to 1 MeV for electrons and 30 keV to 10 MeV for ions. The SPAM instrument uses silicon detectors.
As part of the pre-phase A activities, a new modular and interoperable simulation framework was developed in 2024 by Artenum to support the design and validation of the instrument. This framework is named the SPAM Modelling Framework. This framework integrates and extends existing tools, GEANT4 via GRAS developed by ESA and MoORa, part of SpaceSuite, for primary particle interaction and energy deposition modeling; the EDGE CAD tool, also part of SpaceSuite, for defining detector geometry and material properties; and the Garfield++ library to simulate the incident particles cascade inside the detector.
The framework enables the computation of several key quantities required for the instrument's validation. First, it calculates energy deposition in both dead layer and active region of the detector. Then, it perform a two-step simulation: modeling electron-hole pair creation based on incident particle energy and detector geometry, followed by drift and collection of these charges to compute the resulting current as a function of time.
As an example of application, this modeling chain has been used to evaluate the effects of detector parameters, such as dead layer thickness and bias voltage, on the detector’s ability to discriminate particle species and energies in the Martian environment. The SPAM Modelling Framework has enabled a first-order optimization of the detector's geometry and operating conditions.
Detailed physic results, including experimental validation with a prototype detector, will be presented by IRAP at the 9th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA 2025) in Valencia, Spain.
