Dosimetry is a crucial activity in irradiation campaigns to qualify electronics and materials to operate in radiation environments. Additionally, it also provides means of monitoring radiation levels in accelerator environments to prevent radiation damage to the machines and improve system lifetime. Therefore, this work provides the characterisation of Radio-Photo-Luminescence (RPL) glass dosimeters as a high-level radiation monitor to be used in the mixed radiation fields observed in CERN’s accelerator environment as well as in irradiation campaigns for the qualification of electronic components and materials. Here two methods to improve the measured dose are presented, one for the correction due to the fading of the RPL dosimeters, where an improvement of over 40 % of the measured to the expected dose could be achieved and one method that corrects the measured dose in mixed particle fields to dose in water or air.
The Super Proton Synchrotron (SPS) is the second largest accelerator at CERN where protons are accelerated between 16 GeV/c and 450 GeV/c. Beam losses, leading to the mixed-field radiation of up to MGy magnitude, pose a threat to the reliability of the electronic equipment and polymer materials located in the tunnel and its vicinity. Particularly in the arc sectors, where both main magnets and radiation sensors are periodically arranged, the Total Ionizing Dose (TID) is of concern for the front-end electronics of A Logarithmic Position System (ALPS). The SPS is equipped with multiple radiation detection systems such as Beam Loss Monitors (BLM), RadMons, and as of 2021, the Distributed Optical Fibre Radiation Sensing (DOFRS), that combined all together provide a very comprehensive picture of both the TID spatial distribution and its time evolution. Within this study, the overview of measured 2021 and 2022 TID levels is presented, together with the demonstration of capabilities offered by the different radiation monitors. The DOFRS, supported by the passive Radio-Photo Luminescence (RPL) dosimeter measurements, is used to assess the TID values directly at the electronic racks, which turned out to be reaching several tens of Gy per year, potentially affecting the ALPS lifetime.
Due to the intrinsic masking effects of combinational circuits in digital designs, Single-Event Transient (SET) effects were considered irrelevant compared to the data rupture caused by Single-Event Upset (SEU) effects. However, the importance of considering SET in Very-Large-System-Integration (VLSI) circuits increases given the reduction of the transistor dimensions and the logic data path depth in advanced technology nodes. Accordingly, the threat of SET in electronics systems for space applications must be carefully addressed along with the SEU characterization. In this work, a systematic prediction methodology to assess and improve the SET immunity of digital circuits is presented. Further, the applicability to full-custom and cell-based design methodologies are discussed, and an analysis based on signal probability and pin assignment is proposed to achieve a more application-efficient SET-aware optimization of synthesized circuits. For instance, a SET-aware pin assignment can provide a reduction of 37% and 16% on the SET rate of a NOR gate for a Geostationary Orbit (GEO) and the International Space Station (ISS) orbit, respectively.