Natalia Emriskova

High-energy proton testing is used for single-event effect (SEE) qualification of electronics to be used in several radiation harsh environments. Given the increasing demand, exploiting the capabilities of proton therapy centres for electronics testing may become desirable. In this paper the focus is on the Quirónsalud proton therapy centre, which makes use of a synchrocyclotron to accelerate protons within an energy range of 70-226 MeV. Lower energies can be obtained with degradation. The use of a synchrocyclotron may pose unique challenges for SEE testing, as opposed to the use of a cyclotron, because the time structure of the beam is very complex and very intense instantaneous fluxes are delivered in highly localized areas of the device under test. Independent characterization measurements of the beam time structure and the beam uniformity were performed. SEE testing on some golden chips previously characterized in cyclotron facilities were also accomplished. These showed that the single-event upset (SEU) cross sections measured with this beam are in good agreement with those measured at cyclotrons in the 20-226 MeV proton energy range. As demonstrated by the SEU cross-sections and by the analysis of multiple-cell upsets (MCU), no beam pulse effects are observed that can alter the data collection on the chips despite the very intense instantaneous fluxes. A few limitations were also evidenced when testing with energies below 20 MeV and due to the fixed flux for testing.

Very-high-energy (VHE), heavy ions are of particular interest for single event effects testing due to their combination of high linear energy transfer (LET) and high penetration within electronics components. The dosimetry of such beams poses an important challenge for facilities aiming to provide VHE ions for radiation effects testing. In this paper, ion beam dosimetry using a silicon solid state detector is presented for uranium ions in the 100 – 1000 MeV per nucleon kinetic energy range. The study involves a combination of experimental measurements carried out at the SIS18 accelerator at GSI and Monte Carlo simulation studies using FLUKA. Particular emphasis was put on to the physical basis of interaction between both primary beam particles as well as secondary fragments, and the detector device. Our results demonstrate an excellent capability of understanding key beam properties and extracting the LET through comparison with simulation results. This benchmark study acts as a reference for developing and utilizing a heavy ion electronics testing infrastructure currently under development at CERN.

We present the progress related to CERN’s capacity of delivering highly penetrating, high-LET heavy ions for radiation effect testing of electronic components within the CHIMERA (CHARM High-energy Ions for Micro Electronics Reliability Assurance) project. Profiting from the existing accelerator infrastructure, Monte Carlo simulations and a 300 μm-thick silicon diode, we highlight the beam characterization capabilities and a summary of the beam properties. Finally, we present the comparison of the SRAM SEE cross-section measurements with respect to other heavy ion facilities.

Ultra-high energy (> 5 GeV/n) heavy ion beams exhibit different properties when compared to standard and high energy ion beams. Most notably, fragmentation is a fundamental feature of the beam that may have important implications for electronics testing given the ultra-high energies, and hence ranges, preserved by the fragments. In this work, both the primary lead ion beam, available in the CERN North Area, and its fragments are characterized by means of solid-state detectors. This input is later used to improve the measurements of Single Event Effects in commercial components with this beam. Moreover, the energy deposition distribution in the solid-state detectors is compared to that obtained with Monte Carlo simulations.

Fragmented heavy-ion beams obtained from the interaction of highly energetic ions with thick targets relative to the ion ranges are proposed to mimic the high-penetration linear energy transfer (LET) spectrum present in space and for electronics testing. Our experimental data characterizing fragmented heavy-ion beams show an excellent level of agreement with the Monte Carlo simulations, serving as an initial proof-of-concept of the proposed single-event effect (SEE) testing approach.

The radiation showers generated by the interaction of high-energy electrons with matter include neutrons with an energy distribution peaked at the MeV scale, produced via photonuclear reactions, allowing measurements of neutroninduced Single-Event Effects in electronic devices.In this work we study a setup where the 200-MeV electron beam of the CLEAR accelerator at CERN is directed on an aluminum target to produce a radiation field with a large neutron component.The resulting environment is analyzed by measuring the Single-Event Upset (SEU) and Latchup rates in well-characterized SRAMs, as well as the Total Ionizing Dose in passive Radio-Photo-Luminescence dosimeters, and by comparing the results with predictions from FLUKA simulations.We find that a lateral shielding made of lead protects the SRAMs from an excessive TID rate, yielding an optimal configuration for SEU measurements, particularly in SRAMs that are highly sensitive to MeV-scale neutrons.This setup provides an interesting complementary neutron source with respect to standard neutron facilities based on spallation targets or radioactive sources.

For the Phase-2 upgrade of ATLAS and CMS tracking detectors, a new pixel detector readout chip, with a 50 µm × 50 µm pixel size, is being designed in 65 nm CMOS technology by the RD53 collaboration.A large-scale demonstrator chip called RD53A, is now available.The RD53A chip was designed to withstand a total ionizing dose of 500 Mrad, to operate at thresholds below 1000 e -, with a noise occupancy below 10 -6 and to cope with a hit rate up to 3 GHz cm -2 .It contains design variations in the pixel matrix, among which are three different analog front-ends.A dedicated program of testing and detailed characterization has been devised and carried out to qualify the three front-ends.The key performance parameters for the operation of a pixel detector at High Luminosity LHC, against which the three circuits have been evaluated, are the amount of spurious hits in the detector, caused by the noise and the late hits and the dead time driven by time-over-threshold calibration.

This work discusses the design and the main results relevant to the characterization of analog front-end processors in view of their operation in the pixel detector readout chips of ATLAS and CMS at the High-Luminosity LHC.The front-end channels presented in this paper are part of RD53A, a large scale demonstrator designed in a 65 nm CMOS technology by the RD53 collaboration.The collaboration is now developing the full-sized readout chips for the actual experiments.Some details on the improvements implemented in the analog front-ends are provided in the paper.

The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip.