Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadrons. Moreover, an overview is provided of the standard test approach used to characterize components to be utilized in a high-energy accelerator environment. A set of commercial microelectronic components are tested in a broad range of radiation environments and modeled in the scope of the FLUKA Monte Carlo code leading to the conclusion that, when applying standard test results to the estimation of the high-energy accelerator SEE rate, significant safety margins (quantified in the thesis) need to be applied to account for the risk of the very high-energy particles in the environment

Impact of Energy Dependence on Ground Level and Avionic SEE Rate Prediction When Applying Standard Test Procedures

Single event effects (SEEs) in ground level and avionic applications are mainly induced by neutrons and protons, of which the relative contribution of the latter is larger with increasing altitude. Currently, there are two main applicable standards—JEDEC JESD89A for ground level and IEC 62396 for avionics—that address the procedure for testing and qualifying electronics for these environments. In this work, we extracted terrestrial spectra at different altitudes from simulations and compared them with data available from the standards. Second, we computed the SEE rate using different approaches for three static random access memory (SRAM) types, which present a strong SEE response dependence with energy. Due to the presence of tungsten, a fissile material when interacting with high energy hadrons, the neutron and proton SEE cross sections do not saturate after 200 MeV, but still increase up to several GeV. For these memories, we found standard procedures could underestimate the SEE rate by a factor of up to 4-even in ground level applications—and up to 12 times at 12 km. Moreover, for such memories, the contribution from high energy protons is able to play a significant role, comparable to that of neutrons, even at commercial flight altitudes, and greater at higher altitudes

High-energy hadron testing and in-orbit single-event latchup predictions and boundaries

The volume-equivalent linear energy transfer approach (VELA) was previously proposed in combination with device characterization in a high-energy hadron (HEH) facility for the screening of commercial electronic devices to be used in space. This simplified approach allows determining the space single-event effect rate of a device due to protons and ions with the sole knowledge of the HEH cross-section (and without knowledge of the heavy ion cross-section or the sensitive volume characteristics). Given its simplicity, the method can be limited in terms of applicability to any single-event effect, but its boundaries are not yet known. The latter are investigated by means of Monte-Carlo simulations and experimental data sets to assess the applicability of the VELA to the single-event latchup. This evaluation shows that the main parameters of the VELA are, in fact, unaffected by the potential variability of the heavy ion response and the sensitive volume geometry of the device if a sufficient amount of latchups are observed during the HEH radiation test. However, due to its main approximation, the VELA starts losing its effectiveness when the spectral differences among the energy deposition distributions of the HEH radiation test and the space environment become more important. Nevertheless, such information is used to define the applicability boundaries of the method, which are expressed in terms of a minimum HEH latchup cross-section measured during the test. Finally, the variability of the main parameters of the method with respect to low-Earth orbit mission profiles is also assessed

SEE cross section calibration and application to quasi-monoenergetic and spallation facilities

We describe an approach to calibrate SEE-based detectors in monoenergetic fields and apply the resulting semi-empiric responses to more general mixed-field cases in which a broad variety of particle species and energy spectra are involved. The calibration of the response functions is based both on experimental proton and neutron data and considerations derived from Monte Carlo simulations using the FLUKA code. The application environments include the quasi-monoenergetic neutrons at RCNP, the atmospheric-like VESUVIO spallation spectrum and the CHARM high-energy accelerator test facility

SEE cross section calibration and application to quasi-monoenergetic and spallation facilities

We describe an approach to calibrate SEE-based detectors in monoenergetic fields and apply the resulting semi-empiric responses to more general mixed-field cases in which a broad variety of particle species and energy spectra are involved. The calibration of the response functions is based both on experimental proton and neutron data and considerations derived from Monte Carlo simulations using the FLUKA code. The application environments include the quasi-monoenergetic neutrons at RCNP, the atmospheric-like VESUVIO spallation spectrum and the CHARM high-energy accelerator test facility

Preliminary design of CERN Future Circular Collider tunnel: first evaluation of the radiation environment in critical areas for electronics

As part of its post-LHC high energy physics program, CERN is conducting a study for a new proton-proton collider, called Future Circular Collider (FCC-hh), running at center-of-mass energies of up to 100 TeV in a new 100 km tunnel. The study includes a 90-350 GeV lepton collider (FCC-ee) as well as a lepton-hadron option (FCC-he). In this work, FLUKA Monte Carlo simulation was extensively used to perform a first evaluation of the radiation environment in critical areas for electronics in the FCC-hh tunnel. The model of the tunnel was created based on the original civil engineering studies already performed and further integrated in the existing FLUKA models of the beam line. The radiation levels in critical areas, such as the racks for electronics and cables, power converters, service areas, local tunnel extensions was evaluated

Preliminary design of CERN Future Circular Collider tunnel: first evaluation of the radiation environment in critical areas for electronics

As part of its post-LHC high energy physics program, CERN is conducting a study for a new proton-proton collider, called Future Circular Collider (FCC-hh), running at center-of-mass energies of up to 100 TeV in a new 100 km tunnel. The study includes a 90-350 GeV lepton collider (FCC-ee) as well as a lepton-hadron option (FCC-he). In this work, FLUKA Monte Carlo simulation was extensively used to perform a first evaluation of the radiation environment in critical areas for electronics in the FCC-hh tunnel. The model of the tunnel was created based on the original civil engineering studies already performed and further integrated in the existing FLUKA models of the beam line. The radiation levels in critical areas, such as the racks for electronics and cables, power converters, service areas, local tunnel extensions was evaluated

Advanced In-Situ Instrumentation of RF Circuits for Mixed-Field Irradiation Testing Purpose

This paper presents a method that applies multiplexing and in-fixture calibration technique to qualify for efficient instrumentation of multiple RF circuits up to 6 GHz during mixed-field irradiation

FLUKA Monte Carlo assessment of the terrestrial muon flux at low energies and comparison against experimental measurements

In recent years, there has been an increasing interest in the assessment and modelling of Galactic Cosmic Rays (GCR) particularly regarding the evaluation of the radiation effects on airline crew and passengers, interplanetary missions and on-board microelectronics. In the latter field, today the problem is not just limited to Single Event Effects (SEE) as used in avionics, but is more and more observed at ground level. Galactic cosmic muons, coming from the interaction of primary cosmic rays in the Earth's atmosphere, represent the most numerous species at ground level. In this work, we used the Monte Carlo code FLUKA to assess the atmospheric and terrestrial neutron and muon differential fluxes at various altitudes and specific examples such as the geographic coordinates corresponding to New York City and Vancouver. In this context, particle energy spectra were compared with references available in literature, calculation results obtained by both the QARM and EXPACS codes, as well as recently performed measurements. In addition, the zenith angular distribution, at ground level, was assessed for both neutrons and muons and compared with available references. Differential particle fluxes assessed for Vancouver were used as a primary source to simulate a muon detector currently taking data at TRIUMF to evaluate the passing and stopping terrestrial muon rate under different conditions. Finally, simulations were compared with the experimental measurements made at TRIUMF. Results show an excellent agreement between the FLUKA simulations and both references and the experimental measurements made at TRIUMF