Non-Ionsing Energy Loss (NIEL) calculation software and verification

Develop a robust software for calculation of Non-Ionising Energy Loss (NIEL) for a range of critical space technologies, analyse existing irradiation test data, perform irradiation tests when necessary, map defect centers generated and carry out model verification.  

Non-Ionsing Energy Loss (NIEL) is an important radiation degradation-related parameter for a range of spacecraft sub-systems and components including: Solar cells. Optoelectonic devices. Bipolar transistors. Imaging instrumentation (star trackers, CCDs, photon detectors). Under a previous ESA NPI activity, new NIEL models were developed that improve especially the treatment of energetic electrons. This is important for missions flying in high-intensity electron environments such as GEO Telecom missions, navigation systems (Galileo), and science missions such as JUICE. These new models, named SR-NIEL (for Screened Relativistic) utilise the Geant4 software and have recently been included in the ESA Space Environment Information System (SPENVIS). It is proposed within this activity: To consolidate these models and make the necessary developments. To implement them as separate software classes within the broadly used Geant4 code as well as in space radiation engineering tools such as GRAS and MULASSIS. To extend the models by inclusion of neutron NIEL for ground testing purposes. To extend the framework to also treat heavy ions. To upgrade the existing software for further implementation of the models. To analyse existing NIEL test data. To verify the NIEL models by way of irradiation test campaigns (also employing test samples appropriate for DLTS (Deep-level transient spectroscopy) measurements). DLTS techniques will be used to establish defect concentration and their fundamental parameters.